The present invention relates to a knee-operated switch for a working machine, and particularly a sewing machine, or the like.
German patent specification 1,023,305, which corresponds to U.S. Pat. No. 2,882,817 discloses a knee-operated switch having a switch rod that is displaceable counter to the force of a spring and having a switch contact and which feeds current to a consuming apparatus as a function of its switching state.
Working machines, for example, sewing machines and leatherworking machines, are generally located on or are set into a worktop so that an operator can use them while seated. Machines of this type often have a knee-operated switch located below the worktop, in addition to a pedal. The knee-operated switch triggers particular functions and may be actuated by a force exerted by the operator's knee, e.g. by swinging the knee sideways. Recent design knee-operated switches are so arranged on the underside of the worktop that their positions can be adjusted. This enables the actuating position to be appropriately set as a function of the operator's body dimensions. But such setting of the knee-operated switch is troublesome especially when different operators operate the same working machine.
More modern knee-operated switches are designed with a housing and with an actuating plate that is mounted in a hinge-like manner on the housing. The plate is often glued with sponge rubber inside the housing. The plate includes switches. Such knee-operated switches are comprised of several components, so that their production costs are high. Another disadvantage of known knee-operated switches actuating them requires that a definite force be exerted over a particular switch travel.